Detergent bars having good sudsing and lime soap dispersant characteristics



United States Patent DETERGENT BARS HAVING GOOD SUDSING AND LIME SOAPDISPERSANT CHARACTERISTICS Henry Y. Lew, El Cerrito, Calif, assignor toChevron Research Company, San Francisco, Calif a corporation of DelawareNo Drawing. Filed Mar. 8, 1962, Ser. No. 178,255 12 Claims. (Cl.252--121) This invention relates to detergent bars containing soap whichdo not react with the curd-forming components of hard water tottforminsoluble soaps. The bars may, in addition, contain a syntheticdetergent. More particularly, the detergent bars of the presentinvention contain a lime soap dispersing agent which is either a methyl-B-hydroxyalkyl sulfioxide, an ethyl-B-hydroxyalkyl sulfoxide, or afl-hydroxyethyl-fi-hydr-oxyalkyl sulfoxide. The sulfoxide of the presentinvention inhibits or prevents curd formation of the bar when used inhard Water, and in some instances improves the foam characteristics aswell.

It is well known that the use of ordinary toilet soaps in hard watergives rise to the formation and precipitation of insolublefatty acidssalts, commonly referred to as lime soaps. These precipitated lime soapstend to coagulate and form a sticky curd, which is especially noticeablein Washstands, bathtubs, and the like, Where it rises to the surface ofthe water and adheres around the tub or wash basin as a ring. In laundryapplications the scum or curd affects the laundry tub in like mannerbut, in addition, adheres to the clothes. As a result, the clothes takeon a gray, dingy appearance, develop spots upon ironing, and often arancid odor. Similarly, when used for washing the hair, lime soaps aredeposited thereon, giving the hair a coarse feeling and a dullappearance.

It has now been found that lime soap formation and precipitation can besubstantially avoided by incorporating in the soap, e.g., a tallow soap,a minor but effective amount of a lime-soap dispersing agent which canbe represented by the formula:

Xs-0I-IOHR (l H wherein R is an alkyl group of 8 to 16 carbon atoms,preferably 12 carbon atoms, and X, a member selected from the group ofradicals having the formulae CH (methyl) C H (e'thyl), or HOCH CH (/3-hydroxyethyl). It has further been found that a methyl-,B-hydroxyalkylsulfoxide, an ethyl-[i-hydroxyalkyl sulfoxide, or aB-hydroxyethyl-B-hydroxyalkyl sul'foxide herein contemplated iseffective to inhibit or prevent curd formation without, in the preferredembodiments, substantially impairing the foam properties of the soap.The lime soap dispersing agent of the present invention is effective inamounts ranging from about 5 to 90, preferably to 25, percent by weight,based on soap and lime soap dispersing agent.

The soap which can be used in accordance with the present invention isnot critical. Any of the water-soluble soaps in bar form normally usedin industrial, laundering, and toilet applications are contemplated. Asis known, these soaps can be prepared from a variety of fatty and oilymaterials, such as tallow, coconut oil, cottonseed oil, corn oil,soybean oil, olive oil, palm oil, lard, greases, fish oils, and thelike. The cation portion of the soap is so selected as to impartsufiicient hardness to the soap to form a bar. Thus, the cation can besodium, potassium, or nitrogen-containing, such as the ammonium soaps orthose derived from triethanolamine. In general, water-soluble sodiumsalts of fatty acids derived from tallow and coconut oil are preferredbecause of the ease with which they can be formed into a bar.

As indicated earlier, the invention also encompasses 3,232,879 PatentedF eh. 1, 1966 ternary mixtures of soap, of the type hereinabovedescribed, a methyl-fi-hydroxyalkyl sulfoxide, an ethyl-B- hydroxyalkylsulfoxide, or a 8-hydroxyethyl-fibydroxyalkyl sulfoxide and a syntheticdetergent.

Indeed, it has been proposed in the past to use synthetic detergents,such as the organic alkyl sulf onates, alkyl sulfates, and alkyl benzenesulfonates, admixed with soap, to decrease its curd-forming tendencywhen used in hard water. Even here, however, the problem of lime soapformation and precipitation is not satisfactorily overcome.

The synthetic detergent component, like the soap, is also not critical.Broadly, it falls within the class of surface-active materials which arethe water-soluble salts of organic sufonic acids and Water-soluble saltsof aliphatic sulfuric acid esters. In other Words, synthetic detergentsare contemplated which are water-soluble salts of organic sulfuricreaction products having in the molecular structure either a sulfonicacid or sulfuric acid ester radical.

As more specific examples of satisfactory synthetic detergent, there canbe mentioned the water-soluble salts of alkyl benzene sulfonates,particularly those in which the alkyl group is a polypropylene radicalor other carboncontaining chain, e.g., straight-chain radical, having anaverage of 8 to 15 carbon atoms in the radical; the Watersoluble saltsof alkyl sulfuric acid, having 8 to 18 carbon atoms in the alkyl group;the water soluble salts, such as the alkali metal salts of sulfuric acidesters of primary normal aliphatic alcohols containing 10 to 18 carbonatoms, such as lauryl and oleyl alcohol; primary and secondary alkylsulfates having pronounced detergent power and obtained from primary orsecondary alcohols and olefins. Other examples of the syntheticdetergent component include the sulfuric acid esters which are thewater-soluble salts of sulfuric acid esters of polyhydric alcoholsincompletely esterified with high molecular weight soap-formingcarboxylic acids, such as the Watersoluble salts of sulfuric acid estersof higher molecular weight fatty acids monoglycerides, more specificexamples being sodium glyceryl monolaurate sulfate and potassium.glyceryl monopalmitate sulfate.

Also useful are the water-soluble salts of sulfuric acid esters of thehydroxy ethers resulting from the reaction of an aliphatic alcohol andethylene glycol. These compounds have the general formula:

wherein n-=8 to 20; x=l to 4; and M is an alkali metal. A typicalexample is the sodium salt of lauryl ether of ethylene glycolmonosulfuric acid.

Another type of useful detergents are the watersoluble salts ofmonosulfuric acid esters of the monoethers of lower molecular weightaliphatic alcohols and glycerine. These compounds have the generalformula:

wherein 11:8 to 20 and M is an alkali metal. A typical example is thesodium salt of monolauryl ether of glycerine monosulfuric acid.

Still additional examples of sulfuric acid ester synthetic detergentsare water-soluble salts of sulfated higher fatty acid alkanolamides,such as the sodium salt of sulfated coconut oil fatty acid ethanolamide,and the potassium salt of sulfated tallow oil fatty acidisopropanolamide.

The method of addition of the additive of the present invention is notcritical. It thus can be added to the crutcher after the soap has beenmade by saponification of fats. Or the additive can be added to soapchips and detergent in the amalgamator, if desired, along with othersoap additives conventionally used, such as coloring agents, perfume,fillers and the like.

The ternary mixtures of the invention will generally comprise, in weightpercent, based on soap, synthetic detergent, and lime soap dispersant, 5to 90, preferably 30 to 50, soap; 5 to 90, preferably 30 to 50,synthetic detergent; and 5 to 90, preferably 10 to 40, lime soapdispersant.

In evaluating a satisfactory lime soap dispersant, a good method and theone used in the examples hereinbelow appearing is as follows: A stocksolution of the test dispersant is prepared by dissolving 1 part byweight of the dispersant in 99 parts of distilled water. Stock solutionsof tallow soap and of the various synthetic detergents are alsoprepared, again the concentration of the organic material in thesolution being 1% by weight.

Tallw soap had 5.5% water, and on acidification and extraction withpetroleum ether gave 85.6% fatty acids. The fatty acid component had anacid number of 202 and an iodine number of 50, and contained 2% lauricacid, 4% myrrstrc acid, 33% palmitic acid, 22% stearic acid, and 39%oleic acid.

Since the stock solutions are made up to the same concentration, therelative amount of each solution deter mines the relative percents oftallow soap or tallow soap plus synthetic detergents and dispersant foreach test. For example, a 10% dispersant test is carried out as follows:Place 1 ml. of the dispersant solution and 9 ml. of the tallow soapcontaining solution in the bottom of a 100 ml. stoppered graduatecylinder and swirl it gently. When well mixed, dilute with 90 ml. of 334ppm. hard water (2 parts calcium to 1 part magnesium, calculated ascarbonates) at 110 F. The final hardness is 300 p.p.m. The graduate isthen shaken vigorously for 15 seconds, and then allowed to stand forminutes. At the end of this time, the milliliters of curd and themilliliters of foam are measured and recorded.

The following tabulated examples illustrate the practice of theinvention.

TABLE I Lime soap dispersantsbinary systems (B-hydroxyalkyl sulfoxidesand soap) Ex. Compound Concen- Soap Coneen- M1. M1.

tration tration Curd Foam 1 None Tallow 100% 5 This is the base case,i.e., soap without any dispersant.

i i 2 CH3SCH2CHC10H21 Tallow O 15 In contrast to Example 1, all curd iseliminated, and three times as much foam is formed.

it B 3 CH3SCH2CHC;2H25 15% Tallow 85% O 8 The example shows the effectof increasing chain length 2 carbon atoms over Example 2. The

curd is still eliminated; the foam volume is still greater than thecontrol (Example 1).

i i 4 OH3SO HgCH-C14Hzn 15% Tallow 85% 0 0 No curd formation occurs,though the chain length is increased by two more carbon atoms overExample 3.

r 5 CHsSC 2CHCsH11 15% Tallow 85% O 10 This example shows the eflect ofdecreasing chain length 2 carbon atoms (see Example 2). The

curd is still eliminated and the foam is two times the control value(Example 1).

H i 6 Cl.l3(CHe):S-CIig-CHC@lI13 15% Tallow 85% 10 10 This example usingn-propyl-B-hydroxyoctyl sultoxide is unsatisfactory.

t t 7 CIIaS-CII2-C Il-C14lI29 10% Tallow .c 1 3 This shows the effect ofdecreasing the additive concentration as compared with Example 4. Asmall amount of curd forms, and there is some loam.

it P 8 HO CHZCH2S-CH2CHC1OH 10% Tallow 90% 0 10 This example shows theeffectiveness of fi-hydroxyethyl-fi-hydroxyalkyl sultoxides. All curd iseliminated and good foam is obtained.

H J HO CTIQC l'I a id-C Hz-CIIC1 llp 75% Tallow 25% 0 25 Example 8.

N ow the foam is increased and no curd is formed.

TABLE IContinued Lime soap dispersants-binary systems fl-hydroxyalkylsulfoxides and soap) Ex. Compound Concen- Soap Concen- M1. M1.

tration tration Curd Foam i i 10 HCH2CHSCHzCHC 0Hz1 5% 4:1 Tallow: 95% 2Coconut.

Reducing the additive concentration below the preferred range (seeExample 8) gives some curd, but the foam is satisfactory.

11 OI2H25SO3NEL 20% Tallow 20% 10 20 A commercial polypropylene benzeneSulfonate, a typical detergent, was used in this example.

It does not eliminate curd, although foam property is improved.

12 cinema onion-0101121 15% Tallow 85% 1 15 Ethyl-fl-hydroxyalkylsulfoxides are also effective as shown in this example.

TABLE II Lime soap disper'sants-ternmy system (fl-hydroxyalkylsulfoxide, soap, and a detergent) Ex. Additive Concen- Detergent Concen-Soap Concen- M1. Ml.

tratiou tration tration Curd Foam 1 None None Tallow 100% 10 5 2 .e None Polypropylene benzene Sulfonate Tallow 80% 10 20 This example showsthat the presence of the synthetic detergent has no effect on curd butincreases foam volume.

(H) .C|)H 3 CHa-S-CH2-CH-C10H2r 10% Polypropylene benzene Sulfonate. 20%Tallow 0 12 In contrast .to Examples 1 and 2, the presence of a limesoap dispersant improves the curd property of the composition.

E) (311 a 4 CH3SCHz-CH-Onl12a 10% Polypropylene benzene Sulfonate. 20%Tallow 70% 0 12 I This example shows that increasing the chain lengthfour carbon atoms does not adversely affect foam and curd properties.

r w a -5 HO C'H CH -S+CHz-CHC 1oH21 7% Polypropylene benzene Sulfonate.20% Tallow a. 73% 0 22 Replacement of the methyl group (Example 3) witha 5- ydroxyethyl group still gives good results. Even at a lowerconcentration of additive there is no curd, and the foam is equivalentto .the best.

i r i l 6 H0 CHzCH2-S-CH2-CH-CrqHz1 10% Sodium Lauryl Sulfate -Q 10%Tallow .0 20

The additive of Example 5 is effective with another type of detergent,i.e., a primary sulfate.

r 7 HO CH CII2S-CH CHC11)H21 10% Sodium Paraffin Sulfonate 10% 4:1Tallow: 80% 0 5 Coconut.

1' The paraffin group of the sulfonate is a mixture of C10 to 020straight chain compounds. No curd appears here.

i e '8 U H0 CH2CH2-S-CH2CH-C10H21 5% Mixed Secondary Alcohol Sulfates.10% Tallow l 10 These mixed alcohol sulfates contain alkyl groupsranging from 010 to C20 in carbon content.

. I Compared with Examples 1 and 5, shows that even at very lowconcentrations thls additive reduces curd by a factor of 10 and doublesthe foam.

TABLE IIContinued Lime soap dispersantsternary system (fi-hydroxyalkylsulfoxide, soap, and a detergent) Ex. Additive Concen- Detergent Concen-Soap Concen- M1. M1.

tration tration tration Curd Foam ll i 9 HO CHzCHz-S-CH2-CII-C lI 10%Ammonium Nonylphenol Tetra- 10% Tallow 80% 2 ethylene Glycol Sulfate.

Compared with Example 5, it is shown that the additive still eliminatesall curd with this type of detergent.

0 11 HO CHzCHz--CHzCIIC Hz 10% 1:1 Sodium Lauryl Sulfate:Poly- Tallow70% 0 propylene Benzene Sulionate.

This example shows the additive to function very well with a mixture ofdetergents.

r 11- HO CH CHzSCHzCHC H 65% Polypropylene Benzene Sulfonate- 5%4:1OTalloutr: i 0 25 oconu Even at very high concentrations of additive,the foam properties are excellent, and no curd is formed, as shown inthis example.

r r 12. HO CHzCH2- S CH2OHC H2 10% Polypropylene Benzene Sulfonate. 70%Tallow 20% 0 25 High concentrations of detergent has no adverse erieetson either foam or curd.

i R 13 S CHCHO 11 10% Polypropylene Benzene Sulfonate 20% Tallow 70% 512 Compared with Examples 3 and 5, it is shown that a phenyl group inplace of a methyl or fi-hydroxyethyl group destroys the lime soapdispersant properties.

1] E 14---" OH3(CH2)z S-CH2CHOuH13 10% Polypropylene Benzene Sulfonate.10% Tallow 80% 8 12 Compared with Examples 3 and 5, it is shown that apropyl group in place of a methyl, an ethyl, or B-hydroxydodecyl groupdestroys the lime soap dispersant properties.

ll l 15--- CH3CH2SCEgCHC 0Hz1 10% Polypropylene Benzene Sulfonate. 10%Tallow 80% Trace 12 An ethyl group in place of the methyl group does notsubstantially impair foam and curd-dispersing properties.

I claim: lime soap dispersant is a ,S-hydroxyethyl-fi-hydroxyalkyl 1. Adetergent bar having good sudsing and lime soap dispersantcharacteristics, and suitable for use in hard water consistingessentially of water-soluble solid soap normally having poor lime soapdispersant characteristics, and a lime soap dispersant having theformula XSCHzCH-R (l (m wherein X is a member selected from the groupconsisting of the methyl, ethyl and B-hydroxyethyl radicals, and R, analkyl radical of 8 to 16 carbon atoms; said lime soap dispersant beingpresent in an amount of 5 to 90 percent by weight, based on it and soap.

2. A detergent bar according to claim 1, wherein the lime soapdispersant is present in an amount of 10 to 25 percent.

3. A detergent bar according to claim 1, wherein R is an alkyl radicalof 8 to 12 carbon atoms.

4. A detergent bar according to claim 1, wherein the lime soapdispersant is a methyl-fi-hydroxyalkyl sulfoxide having 10 to 16 carbonatoms in the alkyl group.

5. A detergent bar according to claim 1, wherein the lime soapdispersant is an ethyl-fl-hydroxyalkyl sulfoxide.

6. A detergent bar according to claim 1, wherein the sulfoxide.

7. A detergent bar having good sudsing and lime soap dispersantcharacteristics, and suitable for use in hard water, consistingessentially of a mixture of a water-soluble solid soap and awater-soluble synthetic detergent salt of an organic sulfuric reactionproduct having in its molecular structure a member selected from thegroup consisting of sulfonic acid and sulfuric acid ester radicals, saidmixture having poor lime-soap dispersing characteristics and a lime soapdispersant to impart lime soap dispersing properties to the mixture,said lime soap dispersant having the formula wherein X is a memberselected from the group consisting of the methyl, ethyl, andfi-hydroxyethyl radicals; and R, an alkyl radical of 8 to 16 carbonatoms; the aforesaid ingredients being present in amounts by weightpercent based on soap, lime soap dispersant, and synthetic detergentranging from 5 to soap; 5 to 90 synthetic detergent; and 5 to 90 limesoap dispersant.

8. A detergent bar according to claim 6, wherein the ingredients arepresent in amounts of 30 to 50 percent soap, 30 to 50 percent syntheticdetergent, and 10 to 40 percent lime soap dispersant.

9. A detergent bar according to claim 6 wherein the lime soap dispersanthas the formula wherein X is a member of the group consisting of ethyl,methyl, and hydroxyethyl radicals, and R is an alkyl radical of 8 to 14carbon atoms.

10. A detergent bar according to claim 8, wherein the lime soapdispersant is a methyl-,B-hydroxyalkyl sulfoxide.

11. A detergent bar according to claim 8, v wherein the lime soapdispersant is a hydroXyethyl-fi-hydroxyalkyl sulfoxide.

12. A detergent bar according to claim 8, wherein the lime soapdispersant is an ethyl-B-hydroxyalkyl sulfoxide.

References Cited by the Examiner UNITED STATES PATENTS 2,390,295 12/1945Flett 252121 2,407,647 9/ 1946 Bodman 252-121 2,515,120 7/1950 Harman260607 2,654,667 10/1953 Goodhue et a1 252--161 2,658,038 11/1953 Proell252161 2,749,315 6/1956 Faier 2521 17 2,787,595 4/1957 Webb 2S21383,043,824 7/1962 Oswald et a1 260-607 JULIUS GREENWALD, PrimaryExaminer.

ALBERT T. MEYERS, Examiner.

1. A DETERGENT BAR HAVING GOOD SUDSING AND LIME SOAP DISPERSANTCHARACTERISTICS, AND SUITABLE FOR USE IN HARD WATER CONSISTINGESSENTIALLY OF WATER-SOLUBLE SOLID SOAP NORMALLY HAVING POOR LIME SOAPDISPERSANT CHARACTERISTICS, AND LIME SOAP DISPERSANT HAVING THE FORMULA